Impossible Triangle 3D Optical Illusion

What's wrong with this picture?

This image is taking advantage of the 3D drawing techniques of perspective angles and shading to create this impossible triangle optical illusion. The surfaces and corners of the triangle in are not in the same position they would be if it were a normal triangle, drawn in proper perspective.

The added shading helps us track the surface as intended. Notice the use of different shades at each corner which help make this a believable, impossible form.